Molcas Forum

JianLuo

Member

Registered: 2017-10-25

Posts: 3

[SOLVED] How to change the root when do surface hop

After being excited, one molecule is excited to S2 state (root3), then the S2 state will internal convert to the S1 state (root2) very quickly. After a long time, the new S1 state will internal convert to the ground state (root1). How to reproduce these processes by &SURFACEHOP ?
      When I use &SURFACEHOP, in &RASSCF module, the mdlxroot is defined as 3, because what I am interested in the root3. After the root3 hop to root2, how to tell MOLCAS to simulate the root2 imediately. Otherwise, the MOLCAS will still do molecular dynamics on root3. Thus, the root2 will never internal convert to roo1.
           

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,079

Re: [SOLVED] How to change the root when do surface hop

If your scheme is something like:

&GATEWAY
> Foreach...
&SEWARD
&RASSCF
  mdrlxroot = 3
&SURFACEHOP
&ALASKA
&DYNAMIX
> EndDo

I believe it should do what you want. Of course, you have no control when the hop will happen, the MD and the PES will determine that, and presumably the options you pass to &SURFACEHOP will affect the result. Make sure you don't have "RlxRoot" in &RASSCF too.

JianLuo

Member

Registered: 2017-10-25

Posts: 3

Re: [SOLVED] How to change the root when do surface hop

Thaks for your answer. However, the input you provided can only do the surface hop between root3 and root2. Even though the hop from root3 to root2 happens, the MOLCAS will still do molecular dynamics on root3. What I want is after the hop occurs, the MOLCAS can automatically do molecular dynamics on root2. That is, the mdrlxroot will change from 3 to 2 in the following surface hop calculation.

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,079

Re: [SOLVED] How to change the root when do surface hop

Have you tried it? For me, it works. "MDRlxRoot" is only actually read the first iteration of the loop, in the following iterations what you have in the input does not matter because the program already knows which root it should be following. Check your output. After a successful hop event (search for "A HOP event"), the next RASSCF calculation should be using the new root (search for "Root chosen").

JianLuo

Member

Registered: 2017-10-25

Posts: 3

Re: [SOLVED] How to change the root when do surface hop

Yes, you are right. Thank you very much !!!